a. Field of the Invention
This invention relates generally to attachments or conversions for saws and more particularly to attachments for saws which will allow a saw to perform drilling operations.
b. Prior Art
Radial arm saws are versatile woodworking machines often found at construction sites and in home workshops. A radial arm saw typically includes a horizontal work support table, a vertical column rising from the support table, and a support arm having ways which guide a motor along the length of the arm. The motor is provided with a threaded arbor to which a circular saw blade may be attached. The axis of rotation of the arbor is normally parallel to the work support table but, depending on the orientation of the motor, may attain various angular relationships.
It has been recognized by various persons that the radial arm saw can be adapted or converted so as to perform many different functions, such as drilling or routing. Such an adaption usually involves removing the circular saw blade from the arbor and replacing it with some type of bit holder.
U.S. Pat. Nos. 2,621,686 of J. E. Tompkins, 2,672,170 of A. C. Johnson, 2,811,182 of D. D. Beale et al., and 3,586,079 of W. A. Collins et al., all serve as examples of radial arm saw conversions. For instance, in Thompkins' patent a radial arm saw that can be converted into a vertical drill press is disclosed. In Johnson's patent, a radial arm saw is disclosed which includes a motor that can be turned so as to be vertically disposed for vertical milling operations. Beale et al. disclose a radial arm power tool which again can be used as either a radial arm saw or as a vertical drill press.
The invention of Collins et al. is interesting in that a standard radial arm saw is used to perform both sawing and drilling operations. Collins et al. accomplished this by mounting a conventional radial arm saw upon a specially built mounting base which supports the radial arm saw vertically for sawing operations and which supports it horizontally for drilling operations.
It is apparent from a viewing of the disclosures of Thompkins, Johnson and Beal et al. that there are many types of specialized apparatus which can perform the dual functions of a radial arm saw and a vertical drill press. Such devices are relatively complex and expensive.
The device disclosed in the patent of Collins et al., on the other hand, makes use of a standard and commercially available radial arm saw that is attached to a specially built table that adapts the saw for use as either a saw or as a vertical drill press.